Function:   ROMid()

               This function returns the ROM identification byte.
               This byte is different for ATs, XTs and on other
               machines. This way, it's easy to check whether you
               are running on an AT (and Most 386's use the same
               value). See other manuals for more details about
               possible values.

   Syntax:     ROMid()

   Arguments:  None

   Returns:    A number, representing the Machine ID byte.

   Usage:      if ROMid() <> 252    && AT have Id = 255 (FCh)..
                 ? 'Error, must run on AT computer!'
                 quit
               endif